Over the years, health influencers and nutrition specialists have embraced various weight-loss methods, including the ketogenic diet, liquid cleanses, and strict calorie restriction. Yet, few approaches have garnered as much mainstream attention as intermittent fasting, which has become quite popular.
Regarded by some as a straightforward and effective health tactic, intermittent fasting has sparked endless discussions, with a frequent question emerging: how does it actually work?
Highlights
- A simulation video illustrates how the body reacts during a 36-hour fast, showcasing shifts from ketosis to autophagy.
- Experts note that evidence supporting significant long-term benefits of intermittent fasting in humans is still quite limited.
- Possible drawbacks range from fatigue and nutrient deficiencies to concerns about disordered eating.
As interest in fasting grows, a simulation video from the YouTube channel Wellness Wise guides viewers through the bodily changes that occur over 36 hours without food.
This animation provides an in-depth view of how the body transitions through various metabolic stages, eventually depending more on stored fat for energy—a process linked to fat reduction.
The Video Breakdown
Wellness Wise, which has 198,000 subscribers on YouTube, features a detailed 56-minute video about intermittent fasting. Since its launch a year ago, it has garnered about 28 million views.
The animation is striking, displaying realistic images of human organs and other internal components. The narrator poses the question, “What happens to your body when you fast for 36 hours?” followed by extensive explanations.
According to the video, about four hours post-meal, digestion slows, insulin levels dip, and the body begins to tap into its energy reserves.
After eight hours, the body shifts to utilizing glycogen storage for fuel. At the 12-hour mark, fat burning kicks in as the system heads towards a state known as ketosis, where stored fat becomes the primary energy source.
As the hours progress, various beneficial processes take place. After 16 hours, a cellular repair process called autophagy starts. Around 24 hours in, insulin sensitivity improves, and after 30 hours, growth hormone levels rise, which can help in muscle preservation.
Ultimately, at 36 hours, autophagy reaches its peak, which supports cellular rejuvenation and resets metabolic functions.
Interestingly, Rishi Sunak, the former UK prime minister, is known for participating in a 36-hour fast. According to a source close to him, he would only intake water, tea, or black coffee from 5 PM on Sundays until 5 AM on Tuesdays.
Adam Collins, an associate professor of nutrition at the University of Surrey, has stated that fasting for 36 hours can significantly support weight loss and enhance what’s called “metabolic flexibility,” or the body’s capability to switch fuel sources.
However, experts caution that intermittent fasting isn’t universally safe.
Potential Risks
The Emily Program, a U.S.-based diet and mental health service, has pointed out several side effects related to this practice.
Commonly reported side effects include intense hunger, fatigue, headaches, and mood fluctuations, while more serious risks may involve negative effects on reproductive health and nutrient shortages.
There’s also a noticeable lack of comprehensive data on intermittent fasting. The Emily Program emphasizes that human research remains limited in scope and duration, primarily because such dietary trends are often unsustainable.
James Betts, a metabolic physiology professor at the University of Bath, has echoed these views, despite the growing enthusiasm surrounding intermittent fasting.
Some studies suggest that this method may potentially trigger eating disorders. A December 2022 study involving 2,762 Canadian adolescents and young adults found a notable correlation between intermittent fasting and disordered eating, particularly among women.
The survey revealed that women tended to show stronger associations with disordered eating as a result of fasting practices, compared to men, who exhibited a weaker correlation.
Overall, while many people share their positive experiences with fasting—like increased mental clarity and physical benefits—it’s essential to approach this practice with caution and moderation. In the end, the consensus seems to be that balance is crucial for health and wellbeing.
